Train-control system



June 24, 1930.; w. H. RETCHARD .TRAIN CONTROL SYSTEM Filed April 2v, 1929 .N51 L@ 026s did aan@ @iwi TTORNEY Patented June 24, 193() TAT WADE El. REICHARD, OF ROCHESTER, NEVI YORK, ASSGNOR TO GENERAL RAILWAY SIGNAL COBIPANY, OF ROCHESTER, NEW YORK TRAIN-CQNTROL SYSTEM Application filed April 27,

This invention relates in general to an automatic train control system, and has more particular reference to an intermittent inductive alternating current type ot system such disclosed in the C. S. Bushnell application rler. No. 171,821 tiled March l, 1927.

ln train control systems it is desirable to have cooperating traokway and car-carried apparatus so arranged as to properly inliuence each other over a Wide range ot train speeds, and to be free from liability to short circuits and other defects. It is also desirable that shoulda short-circuit inadvertently occur, it should notresult in a false clear ication.

With regard to the car-carried apparatus more particularly, it is desirable to have properly safeguarded acknowledging and Yet means, whereby such means can not be improperly used to defeat the purposes ol' the system.

Valith the above and other objects in vic it is proposed, in accordance with thisr invention to provide cooperating car-carried and traclu'ay receiver and inductor means capable of adjustment to provide l'or proper operation throughout all speeds of train move nient ever encountered in practice, and arranged so that short-circuits Will not result in talee clear conditions being set up.

lt is also proposed, according to this invention, to safeguard the acknowledging and reset means so that the acknoWledging` means c n not be operated to defeat the usual pun pose of acknowledging, and so that the reset means can not be operated under improper cond tions and so that it must be restored to normal, .after having been operated, betere the 'train can proceed.

Further objects, purposes and cliaraetcristie features Will appear as the description progresses, reference being had to the accompanying draWinOs, showing, solely by Way ot example, and in no manner in a limiting sense, one embodiment which the invention can assume. ln the drawings F l is a schematic View of one embodiment of the invention.

Fig. 2 is a diagram illustrating the operation or portions of the system.

1929. Serial No. 358,577.

Referring now to the drawings, there shown a stretch of single track constituted by track rails l, separated in a usual manner into signalling blocks by insulating joints 2. At the entrance end to each block, travel being in the direction of the arrow, is positioned Wayside signal 3, which is controlled in any usual or desired manner, (not illustrated) to assume'diterent positions so as to give proper indications in accordance vwith traillc conditions ahead. Assuming the iraivr side signals ,are arranged to give three innicatiens, the sig-nal 8 Will be set at stop when block is occupied, Will be set at caution when its block is unoccupied but the block immediately beyond it is occupied, and will beset at proceed When its block and the 'block immediately beyond it are both uiieccupied.

Positioned in the entrance end ol each block is a Wayside conductor lad, constituted by tivo core portions l and 5, with their ends and center portions held together, as illus- 't1-rated, and the interniediate portions beaver,-L out. At each side of the bowed portions, is a laminated sheltl or overhang l1 and 51, to 75 give these parts of the core a double Width for aiding in cooperation With the receiver 'to be described below. These core portions fl and 5 are preferably of laminated material, with the laminations positioned in Vertical planes, for example. Positioned on the cores at each end, are coils 6 and 7, connected up in series with each other through a tuning condenser 8 and a jumper 9, the circuit being adjusted to give a maximum clearing etl'ect .85 tor the core portions adjacent the end coils, .when passed over by a car-carried receiver, to be described below.

Positioned on the core portions l and 5, at an intermediate point, is a middle coil l() which has connected across it a timing corr denser l1, the coil being connected in series with a second tuning condenser l2, a Contact 13 of a line relay LR, and beyond the conta ct 13, an external inductive reactance or retlector ll. i

As indicated, line relay LR, in conjunction with track relay TR and the track relay (not shown) for the block next in advance through a frontpoint of which passes the energizing circuit for LR, automatically controls the position of the contact finger 12:3. in accordance with tratlic conditions, to either open or close the circuitincluding the niiddl.l coil 10, condenser 1Q, and inductive reactanc-i` 14. This control is arranged, so that the ciru cuit is broken under caution and stop condi tions, and is made under proceed conditi'li.-

The jumper' 9 in the circuit including tlvl end coils 6 and 7 can, if desired, be removed so as to remove the shunt around a contact finger' 13l (which is of course without tunetion when so shunted) and thus place these coils under control ot contact finger 13l of relay TR to cause this circuit to be automatically controlled in the same manner as described above with regard to contact 123.

The purposes of the Various controls just described with regard to the inductor wijy appear' as the description progresses.

Carried on the train and preferably on the locomotive or tender, represented diagrammatically by the wheels and axles 15, is carcarried apparatus including a receiver' R comprising a core 16, preferably of laminated material as in the case of the inductor, and in the general form of an H, and positioned as shown so as to pass over the inductor Intl, during travel ot the train, to be affected thereby in a manner to be described.

Carried on the receiver R are two primary windings P, connected in series with each othe' and with a tuning condenser 17, directly across the primary Pr of an alltotransformer T energized trom an alternating current generator 1S, the coudeiracr 1T tuning the primary circuit 'for the frequency employed. which is preferably higher than commercial frequencies may be, tor example, 360 cycles per second.

Also carried on the. receiver R, as shown, are two secondary coils S connected in series with each other and with a tuning condenser 19 and windings Q1 carried on a laminated core QQ of a main relay MR, whereby to energize the windings 21 `and maintain the relay armature. Q3 in picked up position under normal conditions. The secondary circuit is tuned Yfor the 'frequency employed, when the armature 3 is piclied up, but is detuned for this frequency, when the armature is in its released position.

For a more detailed description of the receiver R, reference is made to the appli- 'ation of lV. H. Rcichard, Serial No. 358,578 entitled, Train control car element and filed of even date herewith.

Controlled by the armature Q3, is a valve 24 ar anged. when in its shown position, to close communication between a pipe 25 leading. for example. to the large cylinder of a brake valve actuator. 4and an atmospheric vent port' Q6. The valve Q-lis carried on a stem 2T connected to a springr 2S Atastened to the armature 23, thc spring being retained by a rigid guard Q9.

It is clear itrom the above, that on decnergization ot the main relay MR, the tension spring Bt), will rock armature 23 in a counter-clockwise direction, about its pivot 23l to open valve 21 and thus vent ipe 25, with a resultant automatic brake app ication.

Considering now the co-action between the receiver and the inductor, when entering a clear block the middle co-il 10, as well as end coils 6 and 7, are in closed circuit condition, whereby the distribution of flux furnished by the primary windings l) of the receiver R, and traversing the secondary windings S of the receiver', is not materially disturbed, since the various coils on the inductor operate to choke off passage of flux through the inductor, in very much the same manner as described, in somewhat more detail, in the l. X. Rice application, Serial No. 106,478 filed May 3, 1926. Under such conditions, the secondary windings S of the receiver have suflicient voltages induced therein to supply the main relay windings 21 with sufficient current to maintain armature 23 in attracted position and thus prevent av brake application.

On the train entering a caution or danger block, the inductor middle coil 10 is open circuited at contact 13, condenser 11 connected across winding 1() being so arranged as to give a better stopping effect when contact finger .I- is open, than if the circuit ot winding 1t) were merely open and the condenser were not present to thereby remove the choking clt'ect on all but the end portions of the inductor, so that the flux furnished by the primary coils of the receiver has alternative paths in opposite directions through the receiver secondary windings, so as to reduce the current flow in the secondary circuit, normally energizing the main relay, to a low value, or to zero, or to actually reverse the direction of current flow, all depending on the various constants involved, whereby to cause the main relay to release so as to open valve 24 and cause an automatic brake application. This operation is substantially the same as occurs in the Rice application, referred to above and also in the Rice Australian Patent 3,189 of 1926.

lilith the end windings 6 and 7 of the inductor connected up in a closed circuit, as illustrated, the two ends of the inductor arc choked ofl, so that the receiver is practically unaflected when first passing onto the inductor, and upon leaving the inductor, while the ellect ot' the central portion of the inductor, on the receiver, is determined by the middle coil 10, and the condition of its circuit` automatically controlled by contact finger 13. It the end coils 6 and 7 were open circnited, the ends of the inductor' could operate as permanent stop means, for

de-energizing the secondary windings on the receiver, and always cause a brake application, unless otherwise prevented.

At irst sight itl might be thought that the inductor, as described, might be made shorter by cutting otf its ends, together with the end coils 6 and 7, without atfecting the resulting control by the middle winding 10, but this is not the case.

It the inductor were made of the length shown in the drawing, but not furnished with the two end coils 6 and 7, the receiver, on irstpassing over the inductor, would receive a stop influence, and on leaving the inductor would receive a second stop influence. The first stop influence would con tinue up to the second stop iniiuence, itl the middle coil l0 were open circuited, but there would be a clearing influence, that is, relatively no change below normal in the receiver secondary current, in between, it the middle coil l() be in a closed circuit. The two end coils, when short-circuited as shown, operate to prevent the initiall and final stop influences referred to above, but cause the stop influence, which occurs when the middle coil is open circuited, to be of longer duration than if the ent-ire inductor were made shorter by having its two ends which carry the end coils G and 7, entirely omitted. Thus the two end coils, short-circuited through the condenser 8, do very much more than in effect cutting oif the ends of the inductor.

By this construction which results in the stopping etfect, produeible by the middle coil, being prolonged, a stopping effect can be obtained which is eifective at higher speeds than would otherwise be obtainable. For example, with the present construction a stopping effect which is reliably effective 'for SO miles per hour, might be so shortened in duration by omitting the end coils and the ends of the cores, as to be elfective only 'for speeds up to 4l() miles per hour.

The operation just described, is illustrated in Fig. 2, by the various curves there shown, which represent current induced in the secondary windings S of the car-carried receiver R, plotted against time.

The upper curve 3l represents the secondary current (current in 2l) when the receiver is passing over an inductor at the entrance to a clear block, the current being diminished below normal only slightly, at most, when passing over a clearing inductor.

The curve 32 represents the receiver secon dary current when the receiver passes over a stopping inductor, that is, an inductor with its middle coil l0 open circuited, with the inductor shortened by omitting the end coils G and 7 and the ends of the .inductor core portions 4 and 5. This curve shows that the time during which the secondary current is below the drop-away current value (represented by line for the main relay MR, is relatively short as represented by the line 321.

lVith the inductor constructed as shown in the drawing, i. e., with the ends of the core clicked by 6 and 7, the secondary receiver current, on the receiver passing over a stopping induetor, is represented by the curve 33, Jfrom which it is seen that, due to the short circuited end coils 6 and 7, and the longer inductor core, a considerably greater duration, 331, of current value below dropaway value for the main relay, is realized.

Curve 3e, in Fig. 2, represents the receiver secondary current, on the receiver passing over a stopping inductor in the case where the end coils G and 7, as well as the middle coil 10, is open circuited. It is here seen that the duration, 341, of secondary current below drop-away value for the main relay, is stilll greater than in either of the two previous eases.

From the above description of Fig. 2, it is seen that a very considerable advantage is obtained by using the end coils 6 and 7, in their short circuited connection, over what is obtained by shortening the entire inductor. In other words, the inductor as shown with a single middle coil controlled in accordance with traffic conditions ahead, gives a stopping effect which persists much longer than would be the case without the end coils, although requiring automatic control of only the one winding, l0, on the inductor, i. e., the middle one.

ft is obvious that the higher the speed ot' the train, the shorter the time required for the receiver to traverse the various distances 321, 331 and 351.1, and hence the shorter 'the time during which the main relay is deprived et' energizing current suthcient to maintain it picked up, so that, with the described inductor, means are provided for ad justing it to satisfactorily operate at very high speeds. i

Considering now the operation of the entire system, when a train equipped with the described system enters a. clear block, the receiver R passes in inductive relation over the inductor lmZ, but since the middle winding 10 of the inductor is included in a closed circuit through contact 13 to thus choke bach any iui: through the center portion of the inductor core', the receiver secondary current is not materially affected and the train can proceed past the signal at clear 'without restriction.

It should be noted here, that receiver R, when over the inductor, parallels, and overlies only the shelf parts 4:1 and 51. Thus, with car side sway, movement of the receiver sidewise, can at worst, increase the air gap between the inductor and the receiver, only at one of the two parallel legs of the rece'ver. This shows the advantage of the double width faces produced by parts 4&4?, and

.fl-51, and insurea4 proper control despite side sway.

Assume now that the train entera4 a cantion or danger block, iu which event the inductor is automaticallyv controlled by relay TR to have its middle coil l() open circuito-:l at' the contact' finger 13.

If the engineer be alert, and manifests hi: alertness by operatingy an aeknowledging; contact Arf/r. tl.. the resulting' de-energization of the secondary coil4 S otthe. receiver does not result in rela)r Mil releasing it armature "3 and causing an automatic brake application. The aclinow'ledgjii1g' eontactor is arranged, as sliown. to oirerate normally open contact finge' 51, 511, and a` normally closed contact linger the l normali)v elofwa contact linger 52 being provided n'lth a spring and a retardnig; ineensv 51. whereby contact oper.A ont" son e little 'time after operation ot the contaettor, ari lor atance,

15 seconds thereafter.

(.)n operation ot the a fledgling contactor Aol'. C.. contact fingers 51. 51". and 52 complete a -ireuit Afor 'inergfizing rela)7 MR regardlesjtl of the condition ot the secondary receiver eirenit, such acl nowledging circuity including the Seffontlary Sec. of the anto-tranfiformer, normally closed contact linger aelinowledgiugry ci it et linger 511 and back point', the two wintiingrn 2l. of the main relay MR in steriel; arltnowledging contact linge 5l and lraeli poi it. to the other Lide of the tranaformer weanoarv.

'.lhe tranatormer T ist :to l ad that this; aelmowledging circuit jnat'I referred to Supplies enough current` to the main relay to maintain it` in attracted pmi-lion. but iufsnllcient current to piel( it up atter it in already in retracted porit-ion. Thnx acknowledgment after release ol relataVY )dit i# ineti'eetii'e to reatore tbe relay, while ael:now'ledgment too grat a time prior to reachingr the .it-oppiner iuductor. results in the. aclci nrledgincr circuit beingr brolten by opening oi the nermall \v eio zed contact; tineer of the aeknowledgin; contactor. ln this manner the acknowledging device in protected against'y misuee.

Assume. however. that vigilant'. and does not op edging: contaetor7 then, upon .intr the stopping indue-tor, the second: circuit oil the receiver ll is at least insnncientlf.' euer- ;{ized to maintain the, main rel: armature LJl in its attracted pofniiion. with the. result that such armature rocks in a counter-clockwise direction to open valre to rent the large brake valve acnitor 'cylinder and cause an automatic brake appl'. ion

In order that the train may proceed. the, brakeSv must'` be released. and in order that the brakes he rellen-sed. a remt conti. or Re?. C. must be operated. Thin re=et contacter i5 positioned so as to be :eeeisexble onlJv Vtrom the ground, .so that it lannot be operated until the train han come to a full Stop. 1t might.l here be stated. ol' course, that Speed control meanr; :night be u ed wherebY the rejet eontaetor be yinea eil'eilire onliy at a ver),Y low Speed, su lh as, t'or example, two miles per hour or tle lilie, by use of a spor/I eoutart ot anyY u-uz-l or desired des-ilu auch 'for example an 'own in the tire applieation Ser. No. Tit) il liled August lll-. l.

(/)n the train coniug to a stop. the engb neer can alight and oper: te the reset coutactor so as to cleee the normali",v open contact ingerI 55 and l. to thereby complete a reset circuit including; one side ot the :seeondary of the anto-transl'ormer, contact finger 35 and front', point, the two w'indingx 1, in Series, ot" the n n relayA` reset' contact linger 36 and front peint. a reset tuning condenser 37 and baci; to the other rfide of the transformer seront' rv.

The. tuninr eontaf r`er 1li irs adjuated to tune the reset cirent for the trequenej.' emi: lf,)yed, when the main rela'.y ha@I it#y armature QI) in releaflal position` whereby sulli4 cient current; ilowi`v in the reset circuit to restore the main arnnlture to picked up position and f. to atmosphere.

It Should be noted that the acknowledging` circuit referred to above ineludeal no tuniupr comleuser` and heur-e it ie incapable otI pickingr up the main rela)Y atte' :euch relay llaa once released.

To protect the :eet contaetor from the misurie ot for eminple, tying it in operated position, a rent valve 2lb i,; provided, having a :aten: 31) which in opera 'ed bj' the rI :ret f-oitaeter when in .perated position` to open pipe -Lltl which lianeliese trom pipe 2T, to atmoaphere, through a veut; fill.. In other words, in order to re ztore the main relay .MR to attracted poi-ilion, it is,` neeexsary to vent the pipe Vlea-liner to the brake valve actuator. lt aee'n'diirgly neeesnary, after havin;r operated the re-et contacter, to restore it to its normal poration, (that. shown), before it is possible to release the brakes to permit the train to proceed.

It. will thm` be aeeii that' a :iwi/:n1 l1a1 l-een proridetfl, im'ludin.r ear-carried meana4 havin;r properl)v prtiteetfd and sategnzn'ded ael'\:n \.'ledginer and rt et means, an-'l also iuelnding: cooperatingr imlnvtirebf related earcarrieal and traelira); eceive' and induetor menait, wherein the inductor means can be readilyy adfnated to ent in more or less cortroisl to A:five stoppin' r inliuence` ot varying*r dnrationze, wherebj.' to c: re for varying maximum .Speedo` of train movement.

Referring to the inductor employed in t'hixy System, the` series condenser 12, po :itioned to one side of the antomruieally controlled eontact line/.ir lil, and the Iries inductive reaetance, or external retlector, porsitioned at the other side of contact finger 13, together operate to tune the circuit including the middle inductor coil l0, so as to give the maximum possible clearing effect when the contact 13 is closed. The condenser l2 alone, or the inductive reactance lll alone, gives only very poor or imperfect clearing effect at best.

rlhe wires 42 and 43, which run from the inductor, (which is of course enclosed .in a housing together its coils and condensers), to the external reactor 14, are to some extent necessarily subject to accidental shorts. A short-circuit, however, between these two wires, will include only the series condenser l2 and hence the inductor will be in stopping condition, due to the accidental short. Thus a decided advantage is obtained by placing part of the tuning means at each side of the contact 115, in that accidental shorts can not result in false clear condition. In other words, the disposition of condenser l2 and reactor lei, eliminates the danger due to a short at the points at'which shorts are most lil-:ely to occur.

rllie above rather specilic description of one form of the present invention is given solely by way of illustration, and is not intended, in any manner whatsoever, in a limiting Ubviously, the invention can assume many different physical forms, and is susceptible of numerous modifications, and all such forms and modifications are intended to be included in this application, as come within the scope of the appended claims.

Hzfrving described my invention, I now claim l. In a train control system, in combination, a relay normally energized by alternating current through a circuit tuned, when in attracted position, to the frequency of the alternating current employed, and controlled in accordance with traffic conditions ahead, an armature for the relay, a brake pipe, means controlled by the armature for venting the brake pipe to thereby cause an automatic brake application when the armature is released and to detune said tuned circuit, and reset means operable to complete a tuned energizing circuit for the relay and also to vent said brake pipe.

2. ln a train control system, in combination, a relay normally energized by alternan ing curre t through a. circuit tuned, when in attracted position, to the frequency of the alternating current employed, and controlled in accordance with traffic conditions ahead, an armature for the relay, a brake pipe, means controlled by the armature for venting the bralre pipe to thereby cause an automatic brake application when the armature is released and at the saine time detune said tuned circuit, and acknowledging means operable to complete an energizing` acknowledging circuit for the relay regardless of traliic conditions, said acknowledging circuit being untuned for the frequency of current employed whereby acknowledgement is effective to prevent an automatic brake application only if performed before the relay releases, and reset means operable to complete a tuned energizing circuit for the relay and also to vent said brake pipe.

3. ln train control systems, in combination, a` wayside inductor' having spaced legs, a car-carried receiver having spaced sides and positioned to pass over the inductor in inductive relation thereto, each of the sides being narrower by about one half than the said legs in a direction transverse to the direction of travel, the outer edges of the legs being in vertical line with the outer edges of said spaced sides whereby to prevent car side-sway materially disturbing the indue tive positioning of the inductor and receiver.

el. ln a train control system, in combination, a wayside inductor having spaced parallel legs, each leg having au inverted L. shaped cross section, a car-carried receiver having spaced sides and positioned to pass over the inductor in inductive relation thereto, in a direction transverse to the direction of travel, each of the sides being narrower than the foot of the l. of each said. parallel leg, the outer edges of the sides being in vertical line with the outer edges of the said legs, whereby to prevent car side sway materially disturbing the inductive positioning of the inductor and receiver.

5. In a train control system, in combination, a wayside inductor having spaced parallel legs, each leg having an inverted L shaped cross section, with the feet of the Ls of the parallel legs directed away from each other, a car-carried receiver having spaced sides and positioned to pass over the inductor in inductive relation thereto in a direction transverse to the direction of travel, each of the sides being narrower than the foot of the L of each said parallel leg, the outer edges of the sides being in vertical line with the outer edges of the said legs, whereby to prevent car side sway materially disturbing the inductive positioning of the inductor and receiver.

In testimony whereof I afhx my signature.

.VADE H. RECHARD. 

